Some parts of the image are not filled in

Try the file with bidirectional turned off. If that cleans it up you either have play in your machine or need to perform a scan offset adjustment.

One more opinion: It appears X travel is darker than Y travel. This would indicate it is on the borderline of enough power and not enough. X is burning better because the laser dot is smaller, and thus more intense, on that axis.
A little more power would help and I doubt you would notice a change in the X direction.